Motor-driven compressor



L. D. SAUNDERS. Mo'ToR DmvEN COMPRESSOR.

APPLICATION FILED OCT- 6, |914- Patented Jan. 20, 1920.

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WTNESSES L. D. SAUNDERS. MOTOR DRIVEN COMPRESSOR. APPLICATION FILED ocr.e. I9I4.

Patented Jan. 20, 1920.

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WIITNESSES L. D. SAUNDERS. MOTOR DRlvEN COMPRESSOR.

APPLICATION FILED OCT- 6, |914.

Patented J an. 20, 1920.

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WITNESSES R BRAKE COMPANY, 0F WILMERDING,

MOTOR-DRIVEN COMPRESSOR.

Specification of Letters Patent.

Patented Jan. 2o, 1920.

Application filed October 6, 1914. Serial No. 865,302.

To all whom t may concern:

Be it known that I, LAWRENCE D. SAUN- lnans, a citizen of the UnitedStates, residing at lVilkinsburg, in the county of Allegheny and Stateof Pennsylvania, have invented a certain new and useful .lmprtwement inMotor-Driven i Compressors, of which improvement the following isa'specitication.

This invention relates to air compressors driven by electric motors, andmore particularly to such compressors as are ernploy'ed upon electriccars for compressing air for the air brake system. When used in thisclass ot' service, the' compressor is usuall)v suspended beneath the carbody in such position as to be exposed to dirt, dust., rain, snow andother elements, and must, therefore. be. thoroughly inclosed andprotected therefrom. The available space for the compressor,particularlyr the vertical dimension, is also usually very limited, andone of the objects of my invention is to provide an improved compactstructure of. this type in which the. parts are inclosedand having itsvertical height reduced to a minimum. Another object is to provide animproved driving gear connection between the motor and compressor. andmeans for lubricating the same. Another feature comprises animprovedconstruction of motor casing wherebv the field yoke is independentlysupported and the armature may be readily7 inspected or removed forrepairs when necessary. These and other features of my improvement. willbe hereinafter more fully described. and set forth in the claims.

ln the accompanying drawings: Figure 1 is a horizontal section of amotor compressor embodying my improvement; Fig. 2, a transverse verticalsection taken o n the line .@2 of Fig. 1 g and, Fig. 3, a frontelevation with a portion of the casing broken away to show the drivinggears and bearings for the armature shaft.

According to the construction shown, my improved design comprises acompressor having a closed crank casing, 5, with one or more horizontalcylinders, 6, having the usual suction and discharge valves and openingat their rear ends into the crank chamher` and containing pistons, 7,connected b v rods. 8, with the cranks on the crank shaft.

9, which is mounted in bearings, 10, allv tendency of the shaft, at

within the inclosed chamber. At one end the crank shaft is extendedbeyond the bearing, and is provided with the driving gear, 11, the crankcasing also being extended to inclose sai gear.

The motor casing comprising a rear housing, 12, field yoke, 13, andfront housing, l-l, is located at the side of the compressor casing, andcontains armature, 15, mounted on shaft, 16, and extending through therear housing, 1Q, and into the compressor casing. The side wall of thecrank casing may e 'formed integral with the rear housing, 12. ifdesired, and a long bearing, 16a, is provided in the Sallie for thearmature shaft, the armature being preferably of the overhung typehaving no bearing in the front housing. The armature shaft extends intothe compressor casing in the same horizont-al plane with the crank shaftand the axes of the cylinders, and is provided with the,driving pinion,17. meshing with the gear, 11, of the crank shaft. As the motor casingand the crank casing are of substantially the same vertical height, thislocation of the shafts in the same horizontal plane has the advantage ofreducing the overall height ofthe machine to a minimum.

The armature shaft may also be extended with al beari g, 18, at itsinner end formed in the compressor frame or cylinder. The drivingpinion, 17, is thus located `between the two armature shaft bearings andserves to prevent any wabbling the same time giving a maximum life tothe bearings with minimum wear and a quiet operation of the pinion andgear. An additional advantage derived from the use of the inner bearingfor the armature shaft is that the shaft may be made much smaller indiameter than would otherwise be necessary, and consequently a smallerpinion may be used, which gives the desired speed of rotation andincreases the efficiency of the operation.

The front motor housing, 14, is supported directly upon the rearhousing, 12, by means of the stud bolts, 19, which pass through the eldyoke, 13. This yoke, which is preferably laminated, is thusindependently sus- V pended between the front and rear housings,

and is not itself bolted to the casing; The front housing which coversthe commutator end of the armature is also provided with tom of thecrank case to porting bars, 26.

20, hinged at the bottom and" adapted to be dropped down to expose thearmature and commutator for inspection or removal. The armature and itsshaft may` thus be removed without taking down the compressor, and forthe purpose of detaching the pinion from the shaft, a hand hole plate,21, is provided on the compressor casing o `posite thev pinion, 17,whereby a wrenc may be inserted to hold the nut, 22, by which the pinionis fastened onto the shaft, when the shaft is rotated at the commutatorend. The nut may thus be unscrewed, and the armature and shaft may thenbe drawn out through the front opening. By a reverse operation the partsmay be replaced;

1n order tol lubricate all ofthe moving pants and bearings that requirelubrication, oil is introduced into the bottom of the crank casing to asufficient height that the cranks may splash therein during theirrevolutions. The oil is thus thrown upon the bearings, cylinders, andgears, to eectlv a thorough and continuousV lubrlcatloli. partition, 23,may be employed at the botseparate the gear casing from the oil inthebottom of the crank case, and prevent the' oil from standing` at thesame depthnupon the gear. The movement of the cranks, however, willthrow considerable oil into the gear portion of the casing and the gearwil carry the same up to the pinion and armature shaft bearings withouthaving to churn a large amount of oil unnecessarily. l The cover, 27, ofthe crank case also extends over the gears where it supports an oildefiector, 24, which drains into both armature bearings.

The compressor may be suspended beneath the car by three short verticalhangers, 25', 'bolted to the casing, and bent at right angles at theirupper ends to hook over other sup- By means of the improved constructionas above described, a very compact compressor structure .is producedhaving a minimum overallheight and occupying very little space beneaththe car. v

Having now described my inventiomwhat I claim as new and desire tosecure by Letf ters Patent is:

1. In a motor-driven compressor, the combination of a closed'crankcasing, horizontal cylinders connected therewith, a crank shaft mountedin bearings within the crank cham.

a large door,

I ber, pistons connected .with the cranks, a

within the casing,

gear located on one end of the crank shaft a motor casing at the side ofthe compressor casing, its rear housing being formed integral with theside wall of the crank casing, and containing anelongated bearing at thecylinder side of the crank shaft and in the same horizontal plane Igearon the crank ,mg forthe inner end of the armature shaft ing, a nut onthe therewith, an armature shaft mounted in said bearin and extendingvinto the compressor casing, an armature on said shaft outside of saidelongated bearing, a pinion carried by theI armature shaft within thecompressor casing `and meshing with the shaft, and another bearsupportedon the cylinder wall within the casing.` f

2. 1n a motor driven compressor, the combination of a closed crankcasing, horizontal cylinders connected therewith, a crank shaft mountedin bearings within the, crank chamber, pistons connected with thecranks, a gear located on one end of the crank shaft within the casing,a motor casing at the side of the compressor casing, its rear housingbeing formed integral with the side wall ofthe crank casing, andcontaining an elongated bearing at the cylinder side of the crank shaftand in the same horizontal plane therewith, an armature shaft mounted insaid bearing and extending into the compresser casing, an .armature onsaid shaft outside of said. elongated bearing, a pinion carried by thearmature shaft within the compressor casing and meshing with the gear onthe crank shaft, another bearing for the inner end of the armature shaftsupported on the cylinder wall within the caspinion and the end bearing,and a hand hole cover on the side of the compressor casing opposite thepinion.

3. In a motor driven compressor, the combination of a closed crankcasing,l horizontal cylinders connected therewith, a crank shaftarmature shaft between the mounted in bearings within the crank chamber,istons connected with the cranks, a gear. ocated en one'end of the crankshaft within the casing, a motor casing at the side of the compressorcasing, its rear housing being formed integral with the side wall of thecrank casing, and containing an elongated bearing at the cylinder sideof the crank shaft and in the same horizontal plane therewith, anarmature shaft mounted in said bearing'and extending into the compressorcasing,l an armature on said shaft outside of said elongated bearing, apinion carried by the armature shaft within the compressor `casing andmeshing with the gear on the crank shaft, another bearing for the innerend of the armature shaft supported on the cylinder wall within thecasing, and an oil deiector located over said pinion and draining ontoboth armature bearings.

LAWRENCE D. SAUNDERS. Witnesses:

' A; M.ICLEMEN'rs,

" S. W. KnEFER.

